Lenses already cast light at an angle, the sensor would work just fine with existing lenses, even the field of focus is already curved (if my understanding is correct).

The only problem is lenses corrected for a flat sensor would have a bit of distortion on the edges, but it would have to be pretty severe for most people to care, and Canon could build in a software correction.

No, the image would be defocused towards the edges as the lens is designed (if it's designed properly!) to project a sharp image onto a flat surface, when that surface is curved you're moving the sensor out of that plane of focus.

The whole reason to do this is that it's much easier to design new lenses that focus onto the curved sensor (so less glass = higher quality + lower weight) than onto a flat plane, so that the new lenses won't work with old sensors, and vice versa.

This would be very much like the switch from FD to EF. There'd be converters to allow attaching lenses, but it'd be optically pointless so you'd be better off selling your old glass and investing in new.

It's not a matter of micro focus. A curved sensor is designed for lenses that project an image onto a curved sensor. A normal lens won't work - except perhaps when shot with very narrow apertures where the depth of field is greater therefore the area in focus will be greater.

But otherwise you'd get an area in the center in focus with increasing defocusing as you move towards the edge of the sensor. Maybe you'd be fine with portrait shots. but the wider the aperture the worse the effect would be.

Micro focus won't help because it's nothing that can be adjusted electronically, the only way you'd get a sharp image from an old lens would be to stick it on a tripod and for the camera to automatically stack multiple shots at slightly different focus points to get the whole image in focus.

So, curved sensors really make a lot more sense in fixed-lens cameras than ILCs right now, unless Canon wants to launch a brand new range of lenses from scratch. That's unlikely.

It's not a matter of micro focus. A curved sensor is designed for lenses that project an image onto a curved sensor. A normal lens won't work - except perhaps when shot with very narrow apertures where the depth of field is greater therefore the area in focus will be greater.

But otherwise you'd get an area in the center in focus with increasing defocusing as you move towards the edge of the sensor. Maybe you'd be fine with portrait shots. but the wider the aperture the worse the effect would be.

Micro focus won't help because it's nothing that can be adjusted electronically, the only way you'd get a sharp image from an old lens would be to stick it on a tripod and for the camera to automatically stack multiple shots at slightly different focus points to get the whole image in focus.

So, curved sensors really make a lot more sense in fixed-lens cameras than ILCs right now, unless Canon wants to launch a brand new range of lenses from scratch. That's unlikely.

Not that I'm very knowledgeable about this subject, but would it not be possible to correct a lens designed for a flat sensor with additional optical elements (in an adapter), that distorts the image to accommodate the curved sensor?

So, curved sensors really make a lot more sense in fixed-lens cameras than ILCs right now, unless Canon wants to launch a brand new range of lenses from scratch. That's unlikely.

Not just fixed, but prime. Lenses of different focal lengths require different degrees of curvature. Fortunately, Canon has anticipated this with a patent on a deformable sensor that can adopt varying degrees of curvature...including none (i.e. flat). Thus, such a sensor could work with current flat-field lenses, as well as newly-designed simpler lenses that don't flatten the field.

1) nikon won't do the same thing by trivially removing the mirror from a D850 (which they may still do anyway and probably will because there are some people who want a big dslr for balance). This rumor doesn't negate that possibility at all. In fact, I bet they do both and see what people buy.

There's zero chance anyone would buy a D850 without a mirror installed. If you want to use the D850 without a mirror, you lock it up via the menu. Removing completely hamstrings the camera as Nikon has perhaps the worst on-sensor autofocus available.

1) nikon won't do the same thing by trivially removing the mirror from a D850 (which they may still do anyway and probably will because there are some people who want a big dslr for balance). This rumor doesn't negate that possibility at all. In fact, I bet they do both and see what people buy.

There's zero chance anyone would buy a D850 without a mirror installed. If you want to use the D850 without a mirror, you lock it up via the menu. Removing completely hamstrings the camera as Nikon has perhaps the worst on-sensor autofocus available.

But I still think in the long term to compete with Sony and Nikon that Canon do need to look at a new system that is smaller and lighter (at least when using small primes). The 200D shows that this isn't necessarily impossible with an EF mount, but it comes down to can Canon sell the camera to *new buyers* over the Nikon or Sony offerings. Canon, rightly or wrongly, figure that their existing customers will buy what they have to offer regardless!

Okay, you believe it needs to be small to be market competitive. Understood.

But what is a new buyer? I still (strongly) believe this market -- an FF camera that is anything but a point and shoot -- is not going to be your soccer mom, hockey dad, instagrammer jumping up from cell phone, etc. and walking into a store and buying one. These are four figure investments that generally are made by folks in the know who highly likely have cameras and lenses already (though possibly with a less pricey setup, say an APS-C body with a lens or two).

As such, if you break the market into three chunks...

1) Folks who do not own an ILC2) Existing Canon ILC users3) Competitive ILC users

...Canon is going to go after Group #2 with all its might. They know us from a customer/expectations standpoint and they have us somewhat trapped in the brand with prior glass. We are not a hard sell. short, for Canon, it's quite possibly more profitable knocking on the same old usual customer's door than taking the risk / cost / trouble of trying to the speak the language and fulfill the expectations of the competitive user.

I'm not dismissing the notion of making a new system attractive to camp #1 above, but that's a much bigger deal for the crop market customer, who might walk into a Best Buy, camera store, etc. and see 4-5 different companies' gear side by side. I just don't think FF buyers shop that way nearly as much.

There's zero chance anyone would buy a D850 without a mirror installed. If you want to use the D850 without a mirror, you lock it up via the menu. Removing completely hamstrings the camera as Nikon has perhaps the worst on-sensor autofocus available.

Sure, but if Nikon got its sensor AF working better and put a solid EVF on the body, surely people would buy a mirrorless D850 for a host of reasons (mirrorless 5D4 analogy here).

That said, I don't think Nikon will do that as they are not the market leader -- for them to put a full FX mount on their mirrorless would basically be Nikon putting up a fence around its own customers and saying 'these folks will do, we don't need any others'. I see them going thin and offering an FX adaptor.

Canon, on the other hand, could go full mount (EF) and get away with it. Market leadership + (how many million?) lenses means that aiming a seamless solution to its hordes of shooters might be a higher priority (and much easier sale) than courting Sony and Nikon customers.

But I still think in the long term to compete with Sony and Nikon that Canon do need to look at a new system that is smaller and lighter (at least when using small primes). The 200D shows that this isn't necessarily impossible with an EF mount, but it comes down to can Canon sell the camera to *new buyers* over the Nikon or Sony offerings. Canon, rightly or wrongly, figure that their existing customers will buy what they have to offer regardless!

Okay, you believe it needs to be small to be market competitive. Understood.

But what is a new buyer? I still (strongly) believe this market -- an FF camera that is anything but a point and shoot -- is not going to be your soccer mom, hockey dad, instagrammer jumping up from cell phone, etc. and walking into a store and buying one. These are four figure investments that generally are made by folks in the know who highly likely have cameras and lenses already (though possibly with a less pricey setup, say an APS-C body with a lens or two).

As such, if you break the market into three chunks...

1) Folks who do not own an ILC2) Existing Canon ILC users3) Competitive ILC users

...Canon is going to go after Group #2 with all its might. They know us from a customer/expectations standpoint and they have us somewhat trapped in the brand with prior glass. We are not a hard sell. short, for Canon, it's quite possibly more profitable knocking on the same old usual customer's door than taking the risk / cost / trouble of trying to the speak the language and fulfill the expectations of the competitive user.

I'm not dismissing the notion of making a new system attractive to camp #1 above, but that's a much bigger deal for the crop market customer, who might walk into a Best Buy, camera store, etc. and see 4-5 different companies' gear side by side. I just don't think FF buyers shop that way nearly as much.

- A

Another piece of the puzzle is aps-c, which is very much in the small size race. How well, really, can FF compete as small against aps-c, especially if it is more expensive and the lenses, especially zooms, are bigger (and more expensive)? On CR, we talk a lot about primes, and we may even buy them, but I don't know that there are all that many of us.

It's not a matter of micro focus. A curved sensor is designed for lenses that project an image onto a curved sensor. A normal lens won't work - except perhaps when shot with very narrow apertures where the depth of field is greater therefore the area in focus will be greater.

But otherwise you'd get an area in the center in focus with increasing defocusing as you move towards the edge of the sensor. Maybe you'd be fine with portrait shots. but the wider the aperture the worse the effect would be.

Micro focus won't help because it's nothing that can be adjusted electronically, the only way you'd get a sharp image from an old lens would be to stick it on a tripod and for the camera to automatically stack multiple shots at slightly different focus points to get the whole image in focus.

So, curved sensors really make a lot more sense in fixed-lens cameras than ILCs right now, unless Canon wants to launch a brand new range of lenses from scratch. That's unlikely.

Not that I'm very knowledgeable about this subject, but would it not be possible to correct a lens designed for a flat sensor with additional optical elements (in an adapter), that distorts the image to accommodate the curved sensor?

Yes, but with some loss of quality. You could theoretically have adaptors produced to high precision for specific lenses (or maybe groups of lenses at a similar focal length, eg Canon could produce an adaptor to allow the 'big whites' to work in such a way) but it'd still be one more group of elements in the way reducing quality.

There's zero chance anyone would buy a D850 without a mirror installed. If you want to use the D850 without a mirror, you lock it up via the menu. Removing completely hamstrings the camera as Nikon has perhaps the worst on-sensor autofocus available.

Sure, but if Nikon got its sensor AF working better and put a solid EVF on the body, surely people would buy a mirrorless D850 for a host of reasons (mirrorless 5D4 analogy here).

- A

I fully agree many people would buy a mirrorless camera in a body the size of an SLR.

But for people to buy a D850 without the mirror, nikon would not merely have to get its sensor AF working better, it would have to work as well or better than nikon’s off sensor AF in most shooting scenarios. They might get there in 2-3 generations, but they’re not even close now.

Recall the post I responded to predicted Nikon will trivially remove the mirror from D850 to see what people buy. If they do that, the find that no one buys mirrorless.

Mirrorless 5D4 would be significantly more credible since it has DPAF.

I wonder how small Canon could make a fullframe mirrorless with interchangeable lenses. My guess is they have reached there own conclusions on that question.

I think Sony's gone as afar as you reasonably can - APS-C could go much, much further but you would need to have an APS-C specific mount (Compatibility with FF lenses is what limits the minimum size on Cnon/Nikon APS-C lenses). But some of the criticisms of the Sony is their size - yes, they have improved their interface on the latest modeal (A9 and A7R-III) but people still talk about small buttons hard to operate in some circumstances, particularly when wearing gloves. And on group Canon want to keep are the pros. So that is where I see the smallest size of the first Canon FF mirroless being maybe a bit bigger than the original 6D - maybe even the 5DIV. And once their die-hard Canon fans are happy then, and only then, they will start to experiment with body size.

I fully agree many people would buy a mirrorless camera in a body the size of an SLR.

But for people to buy a D850 without the mirror, nikon would not merely have to get its sensor AF working better, it would have to work as well or better than nikon’s off sensor AF in most shooting scenarios. They might get there in 2-3 generations, but they’re not even close now.

Recall the post I responded to predicted Nikon will trivially remove the mirror from D850 to see what people buy. If they do that, the find that no one buys mirrorless.

Mirrorless 5D4 would be significantly more credible since it has DPAF.

In addition to workable AF, Nikon would have to come up with a high quality Elecronic Viewfinder if if wanted to try to make money with a mirrorless version of the D850. I can't much evidence that Nikon is close to solving the AF or the EVF problems associated with mirrorless FF, but maybe Nikon can pull a rabbit out of the mirrorless hat.

Canon, on the other hand, seems to have a workable approach to AF in a FF mirrorless FF camera based on the 5DIV's Liveview and has marketed an EVF at the aps-c level in the M5.